The invention relates to a radiodiagnostic system including an x-ray tube, a flat picture intensifier, a coupled television camera system, a central unit, and a monitor. Such a radio diagnostic system serves for the reproduction of x-ray pictures on the monitor.
In German patent DE-OS No. 21 41 676 a radio diagnostic system is described where, following the patient in the ray path, an x-ray image intensifier with electron optics is arranged. The reduced output image thereof is taken by a television camera and reproduced on a monitor. By switching the high voltage applied at the electrodes of the x-ray picture intensifier, the electron optics can be varied, so that a certain region of the input field, smaller than the maximum input area, is projected on the output fluorescent screen of the x-ray picture intensifier. Due to this, the parts of the patient traversed by the x-rays appear enlarged on the monitor; such enlargement is called zooming.
In U.S. Pat. No. 4,104,516 a radio diagnostic apparatus is described wherein a beam from an x-ray source is transformed into light by a flat picture intensifier whose output fluorescent screen has the same size as its input screen. Via an optic system the output image of the flat picture intensifier is projected on the target of a television camera and is scanned in a controlled manner by a pilot generator. The scanned video signal is reproduced on the monitor. As an electron-optical magnification does not take place in the flat picture intensifier, the x-ray picture appearing on the monitor cannot be acted upon as to its size by electron-optical changes.